Helical blade mixer

ABSTRACT

A food mixer having vertically disposed parallel shafts with integral helical intermeshing blades on each shaft rotated in opposite directions for selective use to move the food ingredients vertically upwardly or downwardly in a selectable direction in the mixing zone with or without rotation of a mixing bowl. The relative vertical spacing between the blades at their working overlap is adjustable by varying their relative rotational orientation angle to vary their phase relation therebetween whereby the benefits of a wide spacing and a narrow spacing may be had in the mixing overlap zone.

United States Patent Cairelli [15] 3,656,718 [45] Apr. 18, 1972 I54] HELICAL BLADE MIXER [72] Inventor: Carmen P. Cairelli, Farmington, Conn.

[73] Assignee: Dynamics Corporation of America, New

York, NY.

[22] Filed: July 30, 1970 [21] Appl.No.: 59,419

Related U.S. Application Data [63] Continuation-impart of Ser. No. 766,402, Oct. 10,

1968, abandoned.

[52] U.S. Cl ..259/84, 259/104 [51] Int. Cl. ..B01f 9/16 [58] Field ofSearch ..259/l,84, 82,81,DIG. 35,

[56] References Cited UNITED STATES PATENTS 3,314,660 4/1967 Arbiter ..4l6/l22 2,847,198 8/1958 Smith ..416/122 2,766,972 10/1956 Kaufman ..259/51 3,064,908 1 l/ 1962 Hjelte ..259/ 104 2,699,925 l/ 1955 Mad] ..259/DlG. 35

Primary Examiner-Robert W. Jenkins Anorney-l-larbaugh and Thomas [5 7] ABSTRACT A food mixer having vertically disposed parallel shafts with integral helical intermeshing blades on each shaft rotated in opposite directions for selective use to move the food ingredients vertically upwardly or downwardly in a selectable direction in the mixing zone with or without rotation of a mixing bowl. The

relative vertical spacing between the blades at their working overlap is adjustable by varying their relative rotational orientation angle to vary their phase relation therebetween whereby the benefits of a wide spacing and a narrow spacing may be had in the mixing overlap zone.

15 Claims, 10 Drawing Figures P'A'TENTEDAPR 18 I972 SHEET 1 [IF 3 FIG. I

INVENTOR. CARMEN I? CA/RELL/ A Horn eys PATENT EDAPR 18 m2 3.65611 8 SHEET 2 GF 3 FIG. 5

FIG. 4

INVENTOR: CARMEN I? CA/RELL/ By M/fliw Attorneys PATENTEDAPR 18 1872 SHEET 3 BF 3 INVEN TOR: CARMEN P CA/RELL/ A Horn eys IIELICAL BLADE MIXER CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of application Ser.

No. 766,402, filed Oct. 10, 1968, now abandoned.

BACKGROUND OF THE INVENTION DESCRIPTION OF PRIOR ART Food mixers have become standard household appliances in use today for various food mixing operations. Both the stand type mixer and the hand held mixer may be found in nearly every household and are equipped with oppositely rotating drive shafts for interdigitation of two multi-blade beaters. Each beater generally comprises a vertically disposed shaft supporting radially looped and circumferentially spaced blades of flat metal strips adjacent one end and having a releasable clutch at the other end. The two shafts are supported parallel and closely enough that the blades alternately interdigitate when rotated in opposite directions to creat a radially turbulent mixing action.

In order to perform varying mixing operations on the ingredients being used, most of these mixers have a variable speed control. Even with the variable speed control, however, such mixers are limited to use with a relatively fluent material which is objectionably splattered by the blades and are not adapted to operate with highly viscous materials, particularly 4 those which are kneaded without aeration.

SUMMARY OF INVENTION Broadly speaking, the present invention provides a food mixer having first and second substantially parallel shafts extending from and connected to the driving means of the mixer by a clutch disengageable either by ejection, as shown by Swanke et al., Ser. No. 783,260, filed Dec. 12, 1968, or manual pull-out action. Each of the shafts has secured thereto, or made integral therewith, helical blade members extending a substantial distance along the axis of each of the shafts, but providing a pair of oppositely inclined overlapping helices for the two shafts. The shafts are so positioned relative to each other that the helical blades interact with each other so as to perform a mixing or kneading function which drives the material vertically downwardly or upwardly depending on their relative locations with respect to the rotation of the drive shafts. Additionally, the blades may be adjusted rotatively relative to each other so as to change the space phase relationship between the two blades without vertically offsetting the shaft levels.

The invention is also characterized by the interchangeability of the beaters illustrated herein with standard heaters and includes many additional advantages such as reversing the positions of the two heaters to drive the material downwardly or upwardly, and rotating the bowl in either direction accordingly. Moreover, the blades will not splash the fluid contents of the bowl and when raised out of the bowl the mixture clinging will drain down to the lower edge of the helices and drip back to the bow] at? of an edge rather than cling to a flat side of a flat blade.

OBJECTS OF INVENTION It is an object of the present invention to provide a food mixer which is usable with highly viscous as well as fluent materials upon an interchange of beaters of different but overlapping functional characteristics.

It is a further object to provide a mixer which is inherently safe and does not splatter fluent materials while adding viscous ingredients as compared to the standard blade type mixers described above.

Yet another object of the invention is to provide smooth running mixer beaters which eliminate the annoying striking of the bowl which occurs with a conventional beater as it beats against the bowl which is being used.

A further object is to provide a multiple beater mixing relation in which vertically disposed helical beaters can, by interchange between them, force mixing materials either upwardly or downwardly through the mixing zone and in both alternatives either mix the materials by a folding action or by a shearing action, or both, at vertically spaced levels.

A still further object of the present invention is to provide a mixer having a paru'cular type of helical blade construction with adjustable phase relationship between the blades of adjacent shafts without vertically shifting the relative levels of the beater shafts.

Another object is to provide a slicing action for food materials that come between the beaters and the side of the mixing bowl, and, when the bowl is free to rotate, a vertical component of the slicing action, due to the balde helix, will rotate the bowl in a direction which brings the material to the slicing area and to the agitation zone.

These and other objects of this invention including ruggedness, safety, and ease of handling and cleaning will become apparent from the following description when taken in conjunction with the drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a side elevational view of a food mixer utilizing the blades of the present invention, the power unit being shown in full lines as a portable hand mixer with an additional construction shown thereon in broken lines by which the power unit can be supported on a stand to serve as a stand mixer with a rotatable container;

FIG. 2 is an elevational view, partly in section taken on line 2-2 in FIG. 1 with the beater positions reversed from that shown in FIG. 1 with respect to the side of a bowl;

FIG. 2A is a partially sectional view showing the disengageable clutch and supporting means for the shafts of the blades of FIGS. 1 and 2;

FIG. 3 is a partially sectional view of one of the shaft retaining means used in the present invention;

FIG. 4 is a partially broken away plan view of one of the beaters used in the present invention;

FIG. 5 is a partially sectional view showing the details of the upper shaft of FIG. 7;

FIG. 6 is a sectional view taken through the lines 6-6 of FIG. 3;

FIG. 7 is a partially sectional view showing the driving means of one of the shafts;

FIG. 8 is a sectional view taken through the lines 8-8 of FIG. 7; and

FIG. 9 is a sectional view taken through the lines 9-9 of FIG. 7.

DESCRIPTION OF PREFERRED EMBODIMENTS shown in broken lines, for supporting the power unit on a conventional stand 14 in a manner more particularly described in Kennedy U.S. Pat. No. 2,406,150 or Strauss et al. U.S. Pat. No. 2,278,186, reference to which is hereby made. The stand 14 includes a turntable 16 carrying a bowl 18 as rotatably mounted on the pivot pin at 20, and may be rotated by the reaction of the bowl ingredients in the space 24 between the edge 26 of the blade and the side of the bowl.

The two beaters 10R and 10L comprise shafts 15 extending downwardly in working position and carrying helical blades 19. Shaft 15R having helical blade 19R on it is identified by I the letter R' as identifying a right hand helix while shaft 15L and blade 19L identify the shaft and blade having the left hand helix. The two shafts 15 extend downwardly from the power unit 11 in working position and are disposed close enough together as shown in FIGS. 2 and 7 for the blades to overlap a substantial portion of their radial dimension to provide a vertically elongated mixing zone through which the ingredients are carried in the long direction of the mixing zone from the bowl and returned back to the bowl.

The blades 19 are shwon as integral with their respective shafts l and it will be noted that they can be rotated individually in either direction but oppositely with respect to each other for mixing operations.

FIG. 2A shows a sectional view of the shafts 15 together with their encasing shafts 17 upon which the blades 19 are fonned. The shafts 17 are bored internally and are press-fit over internal solid shafts 15. The internal shafts include at their upper ends a set of earns 27 which may be integral with the shafis 15. These cams cooperate with associated garter or C spring retainers 31 which are removably held in place by means of cylindrical drive shafts 40R and 40L within which the internal shafts 15 fit. This arrangement allows either beater to be removed and inserted in either shaft 40. The garter spring reainters 31 expand to allow passage of the cam surfaces 27 into clutched engagement for counter rotation of the two beaters.

FIG. 3 is a more detailed partial sectional view showing the cylindrical drive shaft 40 and one of the garter spring retainers 31 as driven by the wonn gear 24 on the motor shaft 26 and worm wheels 28 engagement therewith carried by the shafts 40. The garter spring fits within an annular groove 45 where it spans longitudinal end slots 43 of both drive shafts 40, preferably oriented in alignment with each other twice each revolution of the two shafts. These slots within the cylindrical drive shafts receive the cam members 27 in proper orientation of equal spacing between overlapping blade portions. By these slots the beaters 10 are forced to rotate therewith.

FIGS. 4 and 5 show in detail the relationship of the outer shaft 17, inner shaft and the integral earns 27 on shaft 15.

One of the desired adjustments provides a means for varying the vertical phase relationship between the overlapping portions of the two helical blades on the cooperating beaters as shown in FIGS. 6 through 9 without relative vertical dislocation of the heaters.

Although it would be possible to vary both of the blades to obtain a phase change, a preferred embodimentis shown wherein the position of one of the blades may be changed while the remaining blade position remains unchanged. This is accomplished by adjusting the angular clutched position of the helical blades of one of the shafts 17. The sectional view of FIG. 6 shows one of the drive shafts 40 as having a plurality of diametral slots 43, 47 and 49. These slots are designed to accept the earns 27 on the inner shaft 15 within the outer shaft 17. This shafi can be either shaft 40R or 40L but is the only one having a set of such slots. Preferably, the slots 47 and 49 are in the shaft 40 nearest to a side of the bowl 18 which in the embodiment illustrated is shaft 40R.

Manually adjusting shaft 17 so that the cams enter either one of the slots 47 or 49 is shown in FIG. 7 by means of the dotted lines relating to the helical blade 19R. This changes the vertical distances between the two sets of blades as they are rotated and, therefore, varies the phase relation therebetween. A blade turn on one beater will be closer to one adjacent turn on the other beater as well as farther from the other adjacent turn on said other beater. This will change the amount of crushing, shearing and mixing effect upon the particular material being worked upon. The closest spacing will shear or crush and the widest spacing will fold and knead and various grades of all of these can be adjusted for. In order to provide a means for indicating the position of the blade for recipe and reference. purposes, a marker 53, or other indicia if desired, may be placed on the housing sleeve 39 and a like marker may be placed on the upper part of shaft 17 as at 55.

The drive system of gears and worm, which is shown is basically a means for rotating the beaters in opposite directions to provide cooperating means by which either beater can be driven in either direction, either singly or doubly, to drive the material either upwardly or downwardly in the mixing zone to provide versatility and superior mixing actions with rugged beaters and adequate power transmission.

Accordingly, the mixer described can mix highly viscous materials and can also knead bread dough or pie crust with no increase in motor capability requirement. Moreover, it. will be obvious to a prospective purchaser as a sale inducement that the shafts with the helical blades are finger" and spoon safe in that placing of either between the shafts would only result in the helical blades driving same vertically out of contact with the blade.

Moreover, the helical beater arrangement is quite silent in operation since the blades can, if desired, with the original tolerances provided, stay in continuous contact with the bowl and progressively clear the wall of the bowl within every few turns of the bowl.

Having thus described the invention it will be understood how the objects are accomplished and how various and further modification can be made without departing from the spirit of the invention.

What is claimed is:

1. A mixer for foods and ingredients of foods comprising,

a housing,

motor means within said housing,

first and second beaters including shaft members extending downwardly from said housing in its working position, said shafts being substantially parallel and the beaters having clutch elements on their upper ends engageable with either shaft,

helical blade members secured to said shafts spiralled in opposite directions and extending a substantial distance vertically along the lower end thereof in radial overlapping relationship to define a mixing zone between the shafts, said shafts being free at the lower end for movement together in and out of a bowl by manual movement of the housing, and

driving means including clutch members releasably engaged by said clutch elements within said housing interconnecting said shafts and said motor means to rotate said shafts in opposite directions of rotation.

2. The mixer of claim 1 wherein said driving means rotates said shafts in opposite directions to move ingredients between them in a vertical direction for repeated return through the beaters.

3. The mixer of claim 2 wherein the blade member on said first shaft has a right-hand helix,

and

the blade member on said second shaft has a left-hand helix.

4. The mixer of claim 1 in which the blade members overlap in a radial direction and are oriented in a phase relationship in which the blade member turns on one of the beaters are closer on one of their sides to the blade turns on the other beater member overlapped thereby than they are on their other side.

5. The mixer of claim 1 including a bowl receiving ingredients and said beaters therein and whose wall is spaced a substantial distance from the beaters over the major portion of the periphery of the beaters to receive from and return to the beaters the ingredients in said bowl.

6. The mixer of claim 5 in which the bowl is rotatably mounted and one of the beaters is located nearest to the wall of the bowl in close proximity thereto and the outer edge of the blade member thereof maintains a constant and narrow space between it and the side of the bowl of a thickness to rotate the bowl with the reaction of the ingredients disposed in said narrow space.

7. The mixer of claim 6 in which said outer edge of the blade member may roll against the wall of the bowl to sever soft ingredients passing through said space.

8. The mixer of claim 1 further comprising,

means for removably securing said blade members interchang'eably to said shafts, and

means for selectively adjusting the relative rotational phase orientation of the helical blade on one shaft with respect to the helical blade on the other shaft.

9. In a mixer for foods and ingredients of foods and having a driving means,

a pair of substantially parallel shafts extending vertically from and releasable clutch means to connect them to the driving means of said mixer in their working positions,

helical blade members extending a substantial distance along the lower ends of each of said shafts in overlapping relationship and being free at their lower ends for manual movement in and out of a bowl, and

the shafts of said pair are rotated in opposite directions with the blade members spiralled in opposite directions and are proximity oriented for said helical blades to interact with each other and perform mixing functions, a component of which is to move the ingredients through a vertical elongated mixing zone.

10. The mixer of claim 9 further comprising,

means for selectively adjusting at least one of said shafts in a relative rotational orientation to change the vertical phase relationship between said blades.

11. The mixer of claim 10 wherein one shaft has a righthand helical blade and the other shaft has a left-hand helical blade.

12. In a mixer for foods and ingredients of foods and having a driving means,

a pair of substantially parallel shafts extending vertically from and releasable clutch means to connect them to the driving means of said mixer in their working positions,

helical blade members extending a substantial distance along the lower ends of each of said shafts in overlapping relationship and being free at their lower ends for manual movement in and out of a bowl and for rotation in opposite directions with the blade members spiralled in opposite directions and are proximity oriented for said helical blades to interact with each other and perform mixing functions, a component of which is to move the ingredients through a vertical elongated mixing zone defined by said overlap,

said clutch means including drive and driven members for each shaft,

three of said members having elements interengageable in two relative rotational positions disposed 180 from each other,

the fourth of said members having elements engageable by two of said three elements at at least three relative rotational positions including two disposed from each other.

13. The mixer of claim 12 in which the other one of said three members and the fourth member are sleeve elements and have corresponding axially disposed slot patterns and said fourth member has at least an additional axial slot in its slot pattern.

'14. A mixer for foods and ingredients of foods comprising,

a housing,

motor means within said housing,

first and second beaters including shaft members extending downwardly from said housing in its working position, said shafts being substantially parallel and the heaters having identical clutch elements on their upper ends,

a helical blade member secured to each of said shafts and extending a substantial distance longitudinally along the lower end thereof, one blade member defining a right hand helix and the other blade member defining a left hand helix and said shafts being free at their lower ends for movement together in and out of a bowl by manual movement of the housing,

driving means including clutch members releasably engaged by said clutch elements within said housing interconnecting said shafts and said motor means to rotate said shafts in o posite directions of rotation said s afts being posltioned so that said helical blades interact with each other so as to perform a mixing function, a component of which is vertical movement of the ingredients through a vertically elongated mixing zone, and

means for selectively adjusting at least one of said shafts in a relative rotational orientation to change the phase relationship between said blades.

15. In a mixer for foods and ingredients of foods,

a pair of substantially parallel shafts extending vertically from and connected to the driving means of said mixer in their working positions,

helical blade members extending a substantial distance along the lower ends of each of said shafts spiralled in opposite directions in overlapping relationship and being free at their lower ends for manual movement in and out of a bowl,

said shafts being positioned so that said helical blades interact with each other so as to perform a mixing function, a component of this is vertical movement of the ingredients through a vertically elongated mixing zone,

means for selectively adjusting at least one of said shafts in a relative rotational orientation to change the phase relationship between said blades. 

1. A mixer for foods and ingredients of foods comprising, a housing, motor means within said housing, first and second beaters including shaft members extending downwardly from said housing in its working position, said shafts being substantially parallel and the beaters having clutch elements on their upper ends engageable with either shaft, helical blade members secured to said shafts spiralled in opposite directions and extending a substantial distance vertically along the lower end thereof in radial overlapping relationship to define a mixing zone between the shafts, said shafts being free at the lower end for movement together in and out of a bowl by manual movement of the housing, and driving means including clutch members releasably engaged by said clutch elements within said housing interconnecting said shafts and said motor means to rotate said shafts in opposite directions of rotation.
 2. The mixer of claim 1 wherein said driving means rotates said shafts in opposite directions to move ingredients between them in a vertical direction for repeated return through the beaters.
 3. The mixer of claim 2 wherein the blade member on said first shaft has a right-hand helix, and the blade member on said second shaft has a left-hand helix.
 4. The mixer of claim 1 in which the blade members overlap in a radial direction and are oriented in a phase relationship in which the blade member turns on one of the beaters are closer on one of their sides to the blade turns on the other beater member overlapped thereby than they are on their other side.
 5. The mixer of claim 1 including a bOwl receiving ingredients and said beaters therein and whose wall is spaced a substantial distance from the beaters over the major portion of the periphery of the beaters to receive from and return to the beaters the ingredients in said bowl.
 6. The mixer of claim 5 in which the bowl is rotatably mounted and one of the beaters is located nearest to the wall of the bowl in close proximity thereto and the outer edge of the blade member thereof maintains a constant and narrow space between it and the side of the bowl of a thickness to rotate the bowl with the reaction of the ingredients disposed in said narrow space.
 7. The mixer of claim 6 in which said outer edge of the blade member may roll against the wall of the bowl to sever soft ingredients passing through said space.
 8. The mixer of claim 1 further comprising, means for removably securing said blade members interchangeably to said shafts, and means for selectively adjusting the relative rotational phase orientation of the helical blade on one shaft with respect to the helical blade on the other shaft.
 9. In a mixer for foods and ingredients of foods and having a driving means, a pair of substantially parallel shafts extending vertically from and releasable clutch means to connect them to the driving means of said mixer in their working positions, helical blade members extending a substantial distance along the lower ends of each of said shafts in overlapping relationship and being free at their lower ends for manual movement in and out of a bowl, and the shafts of said pair are rotated in opposite directions with the blade members spiralled in opposite directions and are proximity oriented for said helical blades to interact with each other and perform mixing functions, a component of which is to move the ingredients through a vertical elongated mixing zone.
 10. The mixer of claim 9 further comprising, means for selectively adjusting at least one of said shafts in a relative rotational orientation to change the vertical phase relationship between said blades.
 11. The mixer of claim 10 wherein one shaft has a right-hand helical blade and the other shaft has a left-hand helical blade.
 12. In a mixer for foods and ingredients of foods and having a driving means, a pair of substantially parallel shafts extending vertically from and releasable clutch means to connect them to the driving means of said mixer in their working positions, helical blade members extending a substantial distance along the lower ends of each of said shafts in overlapping relationship and being free at their lower ends for manual movement in and out of a bowl and for rotation in opposite directions with the blade members spiralled in opposite directions and are proximity oriented for said helical blades to interact with each other and perform mixing functions, a component of which is to move the ingredients through a vertical elongated mixing zone defined by said overlap, said clutch means including drive and driven members for each shaft, three of said members having elements interengageable in two relative rotational positions disposed 180* from each other, the fourth of said members having elements engageable by two of said three elements at at least three relative rotational positions including two disposed 180* from each other.
 13. The mixer of claim 12 in which the other one of said three members and the fourth member are sleeve elements and have corresponding axially disposed slot patterns and said fourth member has at least an additional axial slot in its slot pattern.
 14. A mixer for foods and ingredients of foods comprising, a housing, motor means within said housing, first and second beaters including shaft members extending downwardly from said housing in its working position, said shafts being substantially parallel and the beaters having identical clutch elements on their upper ends, a helical blade meMber secured to each of said shafts and extending a substantial distance longitudinally along the lower end thereof, one blade member defining a right hand helix and the other blade member defining a left hand helix and said shafts being free at their lower ends for movement together in and out of a bowl by manual movement of the housing, driving means including clutch members releasably engaged by said clutch elements within said housing interconnecting said shafts and said motor means to rotate said shafts in opposite directions of rotation, said shafts being positioned so that said helical blades interact with each other so as to perform a mixing function, a component of which is vertical movement of the ingredients through a vertically elongated mixing zone, and means for selectively adjusting at least one of said shafts in a relative rotational orientation to change the phase relationship between said blades.
 15. In a mixer for foods and ingredients of foods, a pair of substantially parallel shafts extending vertically from and connected to the driving means of said mixer in their working positions, helical blade members extending a substantial distance along the lower ends of each of said shafts spiralled in opposite directions in overlapping relationship and being free at their lower ends for manual movement in and out of a bowl, said shafts being positioned so that said helical blades interact with each other so as to perform a mixing function, a component of this is vertical movement of the ingredients through a vertically elongated mixing zone, means for selectively adjusting at least one of said shafts in a relative rotational orientation to change the phase relationship between said blades. 